Device for arresting movement of levers



June 11, 1968 J. WlRTH DEVICE FOR ARRESTING MOVEMENT OF LEVERS Filed Dec. 20, 1966 INVENTOR. JOHPMVE; WIRTh United States Patent 3,387,678 DEVICE FOR ARRESTING MOVEMENT 0F LEVERS Johannes Wirth, Zurich, Switzerland, assignor to Wirth, Gallo & Co., Zurich, Switzerland Filed Dec. 20, 1966, Ser. No. 602,753

Claims priority, applicatiozrgjsggitzerland, Jan. 20, 1966,

1 Claim. (Cl. 177-124) ABSTRACT OF THE DISCLOSURE This invention relates to a device for arresting, for instance in an end position, movable parts of an apparatus, particularly weighing machines, when these parts are lifted off their supporting surface for transportation. Various forms of construction of such arrangements for arresting apparatus during transportation are already known in the art. Usually these require bolts to be tightened at one or more points, levers to be operated, pins or screws to be inserted and so forth. Devices have also been proposed which permit movable parts to be arrested at the necessary points, usually at several points, from a central point with or without the use of a tool. It is a well known fact that it is frequently forgotten to operate such arresting means before the apparatus is lifted and that damage is the result. It is the object of the present invention to provide a simple and reliable arrangement which will prevent inadvertence and forgetfulness from resulting in damage.

The arrangement proposed by the present invention comprises a sensing element urged into contact with the supporting surface on which the apparatus stands, said element causing the apparatus to be automatically arrested when it is lifted off its supporting surface, whereas the apparatus is not automatically released whenit is again deposited on another supporting surface but must be manually released by operation of a lever which functionally co-operates with the sensing element. Energy storage means are also provided for storing the energy supplied during the manual operation of said lever, which energy is then used when automatically arresting the apparatus.

An embodiment of the invention is illustratively shown in the accompanying drawings in which- FIG. 1 is a perspective view of a device according to the invention,

FIG. 2 is a fragmentary section thereof and FIG. 3 is another fragmentary section.

The baseplate 1 of an apparatus, such as a welding machine, carries two mountings 2 and 3 for a shaft 5. A lever 4 is mounted for deflection about this shaft 5. Substantially the lever has the shape of an elongated plate comprising a lateral extension 19 at its free left-hand end, an offangled portion 34 on its edge facing the operator and an upright arm 6 at its right-hand end. The baseplate 1 is further provided with an upright support 12 which carries a locking lever 10 fulcrumed at 11. The free end of the locking lever 11 is movable in guide means 13 and carries a projecting pin 9 connected by a link 8 to a pin 7 on the end of the upright arm 6 of the lever 4. The link 3,387,678 Patented June 11, 1968 and the arm therefore form a pair of hinged toggle levers. A tension spring 17 extends from a hole 16 in the arm 6 to a hole 18 in the baseplate in such manner that the spring urges the upright arm 6 and the lever 4 to swing in the anticlockwise direction.

Underneath the extension 19 on the lever 4 a Z-shaped leaf spring 22 is secured to the baseplate 1 by screws 23. In a bore 25 through the baseplate 1 and in an opening in the angled end 21 of the leaf spring 22 a pin 24 is axially slidably guided. Interposed between the angled end 21 and a transverse retaining pin 32 in the pin 24 is a compression spring 31 which urges the pin 24 into its bottom end position in which the transverse pin 32 rests on the top of the baseplate 1. The weighbridge 14 (only a schematic fraction thereof being shown) has a downwardly directed intermediate member 15 which engages and co-operates with the locking lever 10.

The described arresting mechanism functions as follows. FIG. 1 shows the mechanism in release position. When the Weighing machine is lifted off its supporting surface 26 or off the floor, the spring 31 pushes the pin 24 downwards until the transverse pin 32 is intercepted by the baseplate 1. The spring 17 can therefore now deflect the lever 4, which at first bears on the end 29 of the pin 24 and then rides off the pin, anticlockwise until the lever 4 is in the position indicated in FIG. 2 in dotted lines. The upright arm 6 participates in this deflection and by extending the associated link 8 it raises the free end of the looking lever 10 against the intermediate member 15, thereby pressing the weighbridge 14 against locating stops, not shown in the drawing. In this locked position of the arresting mechanism the bottom end of the pin 24 projects downwards from the underside of the baseplate 1.

As soon as the weighing machine is re-deposited on a supporting surface 26 this pin 24 is again raised against the resistance of the compression spring 31, but the lever 4 remains in position and does not release the weighing machine. For releasing the weighing machine the lever 4 must be raised by the operator taking hold of the offangled edge' 33 and tilting the lever clockwise against the pull of the spring 17. In the course of this upward tilt the right-hand edge 27 of the extension 19 will catch the upper end 29 of the pin 24. However, by giving the lever 4 a harder upward pull the leaf spring 22 can be made to yield and to flex its upper end 29 slightly to the right, thereby permitting the edge 27 to clear the end 29 of the pin. As soon as this is the case the leaf spring 22 will pull the pin 24 back to the left until it snaps into engagement underneath the extension 19. The lever 4 is thus again returned into the position shown in FIG. 1. At the same time the arm 6 has been deflected in the clockwise direction causing the locking lever 10 to be lowered, the weighbridge to be released and the spring 17 to be retensioned. The energy thus stored in the spring 17 is available for automatically re-arresting. the weighing machine when this is lifted off its supporting surface again.

The above described pair of toggle levers, which have a locking effect when in a fully extended position, could be replaced by other self-locking transmission means, such as cams and the like.

' The off-angled edge 34 may be provided with a frame for an inscription such as for instance Lift Here To Release.

FIG. 3 illustrates that this inscription may be so located that the words are clearly visible when the weighing machine is arrested, whereas in released position the words are substantially masked by the side of the casing wall 37. It will be readily understood that other means could be provided for drawing attention to the fact that the machine is arrested.

I claim:

1. A device for arresting movable parts of an apparatus,

3 such as the beam of a weighing scale, when said apparatus is lifted from a support for transportation comprising a base plate of said apparatus, locking lever means pivotally mounted on said base plate and adapted to lock said parts, actuating lever means rotatably mounted on said base plate and having first and second arms, toggle means operatively connecting said first arm to said locking lever means, first spring means connected between said base plate and said first arm to bias said locking lever means towards a locking position, pin means slidably mounted in said base plate, second spring means biasing said pin means into engagement with said support, third spring means biasing said pin means transversely towards engagement with said second arm, whereby when said apparatus rests on a support said pin holds said actuating lever, toggle means and locking lever means in a released condition and when said apparatus is raised from said support said pin releases said actuating lever to be rotated by References Cited UNITED STATES PATENTS 1,544,346 6/1925 Reynolds 177-458 FOREIGN PATENTS 327,176 3/1930 Great Britain.

RICHARD B. WILKINSON, Primary Examiner. G. H. MILLER, JR., Assistant Examiner. 

